The invention relates to a method of withdrawing elongate tubular members from bores in support members. Particularly, the method involves the simultaneous reshaping of the bore for receiving a replacement tubular member.
Where a multiplicity of tubular members is received in a support member for use, for example, in a heat exchanger, evaporator or condenser, it will be appreciated that, in use, corrosion takes place between the tubular members and the support member which renders the original push-fit of the tubular members practically immovable without great difficulty and high labour costs.
Where the heat exchanger or condenser is installed in, for example, a power station, the tubular members may be up to 30 feet or even 70 feet in length requiring a plurality of support members spaced along their length. Moreover the tubular members themselves may number upwards of 200,000, where a plurality of condensers are used in one plant.
The problems hitherto involved in the replacement of such tubular members are enormous. It has been customary to cut the tubular members at locations either side of each support member so that "stubs" project from each bore. The stubs are then individually removed by force and the bore, which has been distorted by corrosion and the removal of the tubular member, afterwards re-shaped by reaming or broaching.
It has been suggested that it might be feasible to withdraw the tubular members by a straight forward pulling action, breaking the corrosion bond at each bore as the tubular member is drawn by the pulling action, but this still leaves the problem of the deformation of the bores.
It is therefore an object of the present invention to provide a method of withdrawing elongate tubular members from bores in support members, which provides a quicker easier operation than heretofore, leaves the bores in a condition for immediate insertion of replacement tubes and also appreciably reduces the time and cost involved when a system of tubular members, such as a condenser system in a power station, is being overhauled.